Systems, methods, and apparatus related to mutual detection and identification of electric vehicle and charging station

ABSTRACT

Systems, methods, and apparatus are disclosed for communicating with a charging system comprising a plurality of charging stations configured to charge an electric vehicle. At least one first signal is transmitted to the charging system via a first communication link while the electric vehicle is a first distance from at least one charging station of the plurality of charging stations. The at least one first signal is indicative of a vehicle identifier of the electric vehicle. At least one second signal is received from the at least one charging station of the plurality of charging stations via a second communication link while the electric vehicle is a second distance from the at least one charging station, the second distance less than the first distance. The at least one second signal is indicative of a charging station identifier of the at least one charging station.

RELATED APPLICATIONS

This application claims the benefit of priority to U.S. ProvisionalAppl. No. 61/846,192, filed Jul. 15, 2013 and incorporated in itsentirety by reference herein and U.S. Provisional Appl. No. 61/904,259,filed Nov. 14, 2013 and incorporated in its entirety by referenceherein.

FIELD

The present disclosure relates generally to wireless power transfer, andmore specifically to devices, systems, and methods related to wirelesspower transfer to remote systems such as vehicles including batteriesand communications therebetween.

BACKGROUND

Remote systems, such as vehicles, have been introduced that includelocomotion power derived from electricity received from an energystorage device such as a battery. For example, hybrid electric vehiclesinclude on-board chargers that use power from vehicle braking andtraditional motors to charge the vehicles. Vehicles that are solelyelectric generally receive the electricity for charging the batteriesfrom other sources. Battery electric vehicles (electric vehicles) areoften proposed to be charged through some type of wired alternatingcurrent (AC) such as household or commercial AC supply sources. Thewired charging connections require cables or other similar connectorsthat are physically connected to a power supply. Cables and similarconnectors may sometimes be inconvenient or cumbersome and have otherdrawbacks. Wireless charging systems that are capable of transferringpower in free space (e.g., via a wireless field) to be used to chargeelectric vehicles may overcome some of the deficiencies of wiredcharging solutions.

In a parking facility with a plurality of charging stations available,an electric vehicle typically navigates within the parking facility tofind a proper parking space for receiving charging from a chargingstation therein. An electric vehicle may attempt to pair with one ormore charging stations within its communication range when a driver isattempting to use a wireless power charging facility with multiplecharging pads. As such, wireless charging systems and methods thatefficiently and effectively facilitate the identification of a chargingstation for a vehicle are needed.

SUMMARY

Various implementations of systems, methods and devices within the scopeof the appended claims each have several aspects, no single one of whichis solely responsible for the desirable attributes described herein.Without limiting the scope of the appended claims, some prominentfeatures are described herein.

Details of one or more implementations of the subject matter describedin this specification are set forth in the accompanying drawings and thedescription below. Other features, aspects, and advantages will becomeapparent from the description, the drawings, and the claims. Note thatthe relative dimensions of the following figures may not be drawn toscale.

One aspect of the subject matter described in the disclosure provides amethod of communicating with a charging system comprising a plurality ofcharging stations configured to charge an electric vehicle. The methodcomprises transmitting at least one first signal to the charging systemvia a first communication link while the electric vehicle is a firstdistance from at least one charging station of the plurality of chargingstations. The at least one first signal is indicative of a vehicleidentifier of the electric vehicle. The method further comprisesreceiving at least one second signal from the at least one chargingstation of the plurality of charging stations via a second communicationlink while the electric vehicle is a second distance from the at leastone charging station of the plurality of charging stations. The seconddistance is less than the first distance. The at least one second signalis indicative of a charging station identifier of the at least onecharging station.

Another aspect of the subject matter described in the disclosureprovides a method of communicating with an electric vehicle. The methodcomprises receiving at least one first signal from the electric vehiclevia a first communication link while the electric vehicle is a firstdistance from at least one charging station of a charging system. The atleast one first signal is indicative of a vehicle identifier of theelectric vehicle. The method further comprises transmitting at least onesecond signal to the electric vehicle via a second communication linkwhile the electric vehicle is a second distance from the at least onecharging station of the charging system. The second distance is lessthan the first distance. The at least one second signal is indicative ofan identifier of at least one charging station of a charging system.

Another aspect of the subject matter described in the disclosureprovides a communication system of an electric vehicle, thecommunication system comprising a transmitter and a first receiver. Thetransmitter is configured to transmit at least one first signal to acharging system via a first communication link while the electricvehicle is a first distance from at least one charging station of aplurality of charging stations of the charging system. The at least onefirst signal is indicative of a vehicle identifier of the electricvehicle. The first receiver is configured to receive at least one secondsignal from the at least one charging station of the plurality ofcharging stations via a second communication link while the electricvehicle is a second distance from the at least one charging station. Thesecond distance is less than the first distance. The at least one secondsignal is indicative of a charging station identifier of the at leastone charging station.

Another aspect of the subject matter described in the disclosureprovides a charging system comprising a receiver and a plurality ofcharging stations. The receiver is configured to receive at least onefirst signal from an electric vehicle via a first communication linkwhile the electric vehicle is a first distance from at least onecharging station of the charging system. The at least one first signalis indicative of a vehicle identifier of the electric vehicle. Theplurality of charging stations comprises the at least one chargingstation and the plurality of charging stations is configured to chargethe electric vehicle. Each charging station of the plurality of chargingstations comprises a first transmitter configured to transmit at leastone second signal via a second communication link while the electricvehicle is a second distance from the at least one charging station. Thesecond distance is less than the first distance. The at least one secondsignal is indicative of an identifier of the at least one chargingstation of the plurality of charging stations.

Another aspect of the subject matter described in the disclosureprovides an apparatus for communicating with a charging systemcomprising a plurality of charging stations configured to charge anelectric vehicle. The apparatus comprises means for transmitting atleast one first signal to the charging system via a first communicationlink while the electric vehicle is a first distance from at least onecharging station of the plurality of charging stations. The at least onefirst signal is indicative of a vehicle identifier of the electricvehicle. The apparatus further comprises means for receiving at leastone second signal from the at least one charging station of theplurality of charging stations via a second communication link while theelectric vehicle is a second distance from the at least one chargingstation. The second distance is less than the first distance. The atleast one second signal is indicative of a charging station identifierof the at least one charging station.

Another aspect of the subject matter described in the disclosureprovides an apparatus for communicating with an electric vehicle. Theapparatus comprises means for receiving at least one first signal fromthe electric vehicle via a first communication link while the electricvehicle is a first distance from at least one charging station of acharging system. The at least one first signal is indicative of avehicle identifier of the electric vehicle. The apparatus furthercomprises means for transmitting at least one second signal via a secondcommunication link while the electric vehicle is a second distance fromthe at least one charging station of the charging system. The seconddistance is less than the first distance. The at least one second signalis indicative of an identifier of at least one charging station of acharging system.

Another aspect of the subject matter described in the disclosureprovides a non-transitory computer-readable medium comprising code that,when executed, causes an apparatus to transmit at least one first signalto the charging system via a first communication link while an electricvehicle is a first distance from at least one charging station of aplurality of charging stations. The at least one first signal isindicative of a vehicle identifier of the electric vehicle. The code,when executed, further causes the apparatus to receive at least onesecond signal from the at least one charging station of the plurality ofcharging stations via a second communication link while the electricvehicle is a second distance from the at least one charging station. Thesecond distance is less than the first distance. The at least one secondsignal is indicative of a charging station identifier of the at leastone charging station.

Another aspect of the subject matter described in the disclosureprovides a non-transitory computer-readable medium comprising code that,when executed, causes an apparatus to receive at least one first signalfrom an electric vehicle via a first communication link while theelectric vehicle is a first distance from at least one charging stationof a charging system. The at least one first signal is indicative of avehicle identifier of the electric vehicle. The code, when executed,further causes the apparatus to transmit at least one second signal viaa second communication link while the electric vehicle is a seconddistance from the at least one charging station. The second distance isless than the first distance. The at least one second signal isindicative of an identifier of the at least one charging station of thecharging system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an exemplary wireless power transfer system forcharging an electric vehicle, in accordance with an exemplary embodimentof the invention.

FIG. 2 is a schematic diagram of exemplary components of the wirelesspower transfer system of FIG. 1.

FIG. 3 is another functional block diagram showing exemplary core andancillary components of the wireless power transfer system of FIG. 1.

FIG. 4 is a functional block diagram showing a replaceable contactlessbattery disposed in an electric vehicle, in accordance with an exemplaryembodiment of the invention.

FIGS. 5A, 5B, 5C, and 5D are diagrams of exemplary configurations forthe placement of an induction coil and ferrite material relative to abattery, in accordance with exemplary embodiments of the invention.

FIG. 6 is a chart of a frequency spectrum showing exemplary frequenciesthat may be used for wireless charging an electric vehicle, inaccordance with an exemplary embodiment of the invention.

FIG. 7 is a chart showing exemplary frequencies and transmissiondistances that may be useful in wireless charging electric vehicles, inaccordance with an exemplary embodiment of the invention.

FIG. 8A is a functional block diagram of an exemplary multi-vehicle andmulti-parking parking and charging system, in accordance with variousimplementations.

FIG. 8B schematically illustrates an example sequence of communicationbetween the BCC, the BCUs, and the vehicle in accordance with certainembodiments described herein.

FIG. 9A is an example state diagram for a vehicle in accordance withcertain embodiments described herein and FIGS. 9B-9E are example flowdiagrams corresponding to the various states.

FIG. 10 is an example flow diagram for the communications between thevehicle and the BCC in accordance with certain embodiments describedherein.

FIG. 11 is an example diagram of the signals sent among the vehicle, theBCC, and the BCUs (e.g., BCU1, BCU2, BCU3) in an automatic chargingspace selection process in accordance with certain embodiments describedherein.

FIG. 12 is a flowchart of an exemplary method for exchangingcommunication between a charging system and an electric vehicle inaccordance with an exemplary embodiment.

FIG. 13 illustrates a flowchart of an exemplary method of communicatingwith a charging system comprising a plurality of charging stationsconfigured to charge an electric vehicle, in accordance with certainembodiments described herein.

FIG. 14 illustrates a flowchart of an exemplary method of communicatingwith an electric vehicle in accordance with certain embodimentsdescribed herein.

FIG. 15 is a functional block diagram of an apparatus for communicatingwith a charging system comprising a plurality of charging stationsconfigured to charge an electric vehicle, in accordance with certainembodiments described herein.

FIG. 16 is a functional block diagram of an apparatus for communicatingwith an electric vehicle in accordance with certain embodimentsdescribed herein.

The various features illustrated in the drawings may not be drawn toscale. Accordingly, the dimensions of the various features may bearbitrarily expanded or reduced for clarity. In addition, some of thedrawings may not depict all of the components of a given system, methodor device. Finally, like reference numerals may be used to denote likefeatures throughout the specification and figures.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of exemplary embodiments of theinvention and is not intended to represent the only embodiments in whichthe invention may be practiced. The term “exemplary” used throughoutthis description means “serving as an example, instance, orillustration,” and should not necessarily be construed as preferred oradvantageous over other exemplary embodiments. The terms “first,”“second,” and “third” are used herein to distinguish among variouselements (e.g., “first signal,” “second signal,” and “third signal”) andare not intended to denote any particular order to these elements (e.g.,are not intended to denote any particular order to the transmission ofthe first, second, or third signals or the reception of the first,second, or third signals). The detailed description includes specificdetails for the purpose of providing a thorough understanding of theexemplary embodiments of the invention. In some instances, some devicesare shown in block diagram form.

Wirelessly transferring power may refer to transferring any form ofenergy associated with electric fields, magnetic fields, electromagneticfields, or otherwise from a transmitter to a receiver without the use ofphysical electrical conductors (e.g., power may be transferred throughfree space). The power output into a wireless field (e.g., a magneticfield) may be received, captured by, or coupled by a “receiving coil” toachieve power transfer.

An electric vehicle is used herein to describe a remote system, anexample of which is a vehicle that includes, as part of its locomotioncapabilities, electrical power derived from a chargeable energy storagedevice (e.g., one or more rechargeable electrochemical cells or othertype of battery). As non-limiting examples, some electric vehicles maybe hybrid electric vehicles that include besides electric motors, atraditional combustion engine for direct locomotion or to charge thevehicle's battery. Other electric vehicles may draw all locomotionability from electrical power. An electric vehicle is not limited to anautomobile and may include motorcycles, carts, scooters, and the like.By way of example and not limitation, a remote system is describedherein in the form of an electric vehicle (EV). Furthermore, otherremote systems that may be at least partially powered using a chargeableenergy storage device are also contemplated (e.g., electronic devicessuch as personal computing devices and the like).

FIG. 1 is a diagram of an exemplary wireless power transfer system 100for charging an electric vehicle 112, in accordance with an exemplaryembodiment of the invention. The wireless power transfer system 100enables charging of an electric vehicle 112 while the electric vehicle112 is parked near a base wireless charging system 102 a. Spaces for twoelectric vehicles are illustrated in a parking area to be parked overcorresponding base wireless charging system 102 a and 102 b. In someembodiments, a local distribution center 130 may be connected to a powerbackbone 132 and configured to provide an alternating current (AC) or adirect current (DC) supply through a power link 110 to the base wirelesscharging system 102 a. The base wireless charging system 102 a alsoincludes a base system induction coil 104 a for wirelessly transferringor receiving power and an antenna 136. An electric vehicle 112 mayinclude a battery unit 118, an electric vehicle induction coil 116, anelectric vehicle wireless charging system 114, and an antenna 140. Theelectric vehicle induction coil 116 may interact with the base systeminduction coil 104 a for example, via a region of the electromagneticfield generated by the base system induction coil 104 a.

In some exemplary embodiments, the electric vehicle induction coil 116may receive power when the electric vehicle induction coil 116 islocated in an energy field produced by the base system induction coil104 a. The field corresponds to a region where energy output by the basesystem induction coil 104 a may be captured by an electric vehicleinduction coil 116. For example, the energy output by the base systeminduction coil 104 a may be at a level sufficient to charge or power theelectric vehicle 112 (e.g., to charge the battery unit 118). In somecases, the field may correspond to the “near field” of the base systeminduction coil 104 a. The near-field may correspond to a region in whichthere are strong reactive fields resulting from the currents and chargesin the base system induction coil 104 a that do not radiate power awayfrom the base system induction coil 104 a. In some cases the near-fieldmay correspond to a region that is within about ½π of wavelength of thebase system induction coil 104 a (and vice versa for the electricvehicle induction coil 116) as will be further described below.

Local distribution center 130 may be configured to communicate withexternal sources (e.g., a power grid) via a communication backhaul 134,and with the base wireless charging system 102 a via a communicationlink 108.

Base wireless charging systems 102 a and 102 b may be configured tocommunicate with the electric vehicle wireless charging system 114 viaantennas 136 and 138. For example, the wireless charging system 102 amay communicate with the electric vehicle wireless charging system 114using a communication channel between antennas 138 and 140. Thecommunication channels may be any type of communication channels suchas, for example, Bluetooth, zigbee, cellular, wireless local areanetwork (WLAN), etc.

In some embodiments the electric vehicle induction coil 116 may bealigned with the base system induction coil 104 a and, therefore,disposed within a near-field region simply by the driver positioning theelectric vehicle 112 correctly relative to the base system inductioncoil 104 a. In other embodiments, the driver may be given visualfeedback, auditory feedback, or combinations thereof to determine whenthe electric vehicle 112 is properly placed for wireless power transfer.In yet other embodiments, the electric vehicle 112 may be positioned byan autopilot system, which may move the electric vehicle 112 back andforth (e.g., in zig-zag movements) until an alignment error has reacheda tolerable value. This may be performed automatically and autonomouslyby the electric vehicle 112 without or with only minimal driverintervention provided that the electric vehicle 112 is equipped with aservo steering wheel, ultrasonic sensors, and intelligence to adjust thevehicle. In still other embodiments, the electric vehicle induction coil116, the base system induction coil 104 a, or a combination thereof mayhave functionality for displacing and moving the induction coils 116 and104 a relative to each other to more accurately orient them and developmore efficient coupling therebetween.

The base wireless charging system 102 a may be located in a variety oflocations. As non-limiting examples, some suitable locations include aparking area at a home of the electric vehicle 112 owner, parking areasreserved for electric vehicle wireless charging modeled afterconventional petroleum-based filling stations, and parking lots at otherlocations such as shopping centers and places of employment.

Charging electric vehicles wirelessly may provide numerous benefits. Forexample, charging may be performed automatically, virtually withoutdriver intervention and manipulations thereby improving convenience to auser. There may also be no exposed electrical contacts and no mechanicalwear out, thereby improving reliability of the wireless power transfersystem 100. Manipulations with cables and connectors may not be needed,and there may be no cables, plugs, or sockets that may be exposed tomoisture and water in an outdoor environment, thereby improving safety.There may also be no sockets, cables, and plugs visible or accessible,thereby reducing potential vandalism of power charging devices. Further,since an electric vehicle 112 may be used as distributed storage devicesto stabilize a power grid, a docking-to-grid solution may be used toincrease availability of vehicles for Vehicle-to-Grid (V2G) operation.

A wireless power transfer system 100 as described with reference to FIG.1 may also provide aesthetical and non-impedimental advantages. Forexample, there may be no charge columns and cables that may beimpedimental for vehicles and/or pedestrians.

As a further explanation of the vehicle-to-grid capability, the wirelesspower transmit and receive capabilities may be configured to bereciprocal such that the base wireless charging system 102 a transferspower to the electric vehicle 112 and the electric vehicle 112 transferspower to the base wireless charging system 102 a e.g., in times ofenergy shortfall. This capability may be useful to stabilize the powerdistribution grid by allowing electric vehicles to contribute power tothe overall distribution system in times of energy shortfall caused byover demand or shortfall in renewable energy production (e.g., wind orsolar).

FIG. 2 is a schematic diagram of exemplary components of the wirelesspower transfer system 100 of FIG. 1. As shown in FIG. 2, the wirelesspower transfer system 200 may include a base system transmit circuit 206including a base system induction coil 204 having an inductance L₁. Thewireless power transfer system 200 further includes an electric vehiclereceive circuit 222 including an electric vehicle induction coil 216having an inductance L₂. Embodiments described herein may usecapacitively loaded wire loops (i.e., multi-turn coils) forming aresonant structure that is capable of efficiently coupling energy from aprimary structure (transmitter) to a secondary structure (receiver) viaa magnetic or electromagnetic near field if both primary and secondaryare tuned to a common resonant frequency. The coils may be used for theelectric vehicle induction coil 216 and the base system induction coil204. Using resonant structures for coupling energy may be referred to“magnetic coupled resonance,” “electromagnetic coupled resonance,”and/or “resonant induction.” The operation of the wireless powertransfer system 200 will be described based on power transfer from abase wireless power charging system 202 to an electric vehicle 112, butis not limited thereto. For example, as discussed above, the electricvehicle 112 may transfer power to the base wireless charging system 102a.

With reference to FIG. 2, a power supply 208 (e.g., AC or DC) suppliespower P_(SDC) to the base wireless power charging system 202 to transferenergy to an electric vehicle 112. The base wireless power chargingsystem 202 includes a base charging system power converter 236. The basecharging system power converter 236 may include circuitry such as anAC/DC converter configured to convert power from standard mains AC to DCpower at a suitable voltage level, and a DC/low frequency (LF) converterconfigured to convert DC power to power at an operating frequencysuitable for wireless high power transfer. The base charging systempower converter 236 supplies power P₁ to the base system transmitcircuit 206 including the capacitor C₁ in series with the base systeminduction coil 204 to emit an electromagnetic field at a desiredfrequency. The capacitor C₁ may be provided to form a resonant circuitwith the base system induction coil 204 that resonates at a desiredfrequency. The base system induction coil 204 receives the power P₁ andwirelessly transmits power at a level sufficient to charge or power theelectric vehicle 112. For example, the power level provided wirelesslyby the base system induction coil 204 may be on the order of kilowatts(kW) (e.g., anywhere from 1 kW to 110 kW or higher or lower).

The base system transmit circuit 206 including the base system inductioncoil 204 and electric vehicle receive circuit 222 including the electricvehicle induction coil 216 may be tuned to substantially the samefrequencies and may be positioned within the near-field of anelectromagnetic field transmitted by one of the base system inductioncoil 204 and the electric vehicle induction coil 116. In this case, thebase system induction coil 204 and electric vehicle induction coil 116may become coupled to one another such that power may be transferred tothe electric vehicle receive circuit 222 including capacitor C₂ andelectric vehicle induction coil 116. The capacitor C₂ may be provided toform a resonant circuit with the electric vehicle induction coil 216that resonates at a desired frequency. Element k(d) represents themutual coupling coefficient resulting at coil separation. Equivalentresistances R_(eq,1) and R_(eq,2) represent the losses that may beinherent to the induction coils 204 and 216 and the anti-reactancecapacitors C₁ and C₂. The electric vehicle receive circuit 222 includingthe electric vehicle induction coil 316 and capacitor C₂ receives powerP₂ and provides the power P₂ to an electric vehicle power converter 238of an electric vehicle charging system 214.

The electric vehicle power converter 238 may include, among otherthings, a LF/DC converter configured to convert power at an operatingfrequency back to DC power at a voltage level matched to the voltagelevel of an electric vehicle battery unit 218. The electric vehiclepower converter 238 may provide the converted power P_(LDC) to chargethe electric vehicle battery unit 218. The power supply 208, basecharging system power converter 236, and base system induction coil 204may be stationary and located at a variety of locations as discussedabove. The battery unit 218, electric vehicle power converter 238, andelectric vehicle induction coil 216 may be included in an electricvehicle charging system 214 that is part of electric vehicle 112 or partof the battery pack (not shown). The electric vehicle charging system214 may also be configured to provide power wirelessly through theelectric vehicle induction coil 216 to the base wireless power chargingsystem 202 to feed power back to the grid. Each of the electric vehicleinduction coil 216 and the base system induction coil 204 may act astransmit or receive induction coils based on the mode of operation.

While not shown, the wireless power transfer system 200 may include aload disconnect unit (LDU) to safely disconnect the electric vehiclebattery unit 218 or the power supply 208 from the wireless powertransfer system 200. For example, in case of an emergency or systemfailure, the LDU may be triggered to disconnect the load from thewireless power transfer system 200. The LDU may be provided in additionto a battery management system for managing charging to a battery, or itmay be part of the battery management system.

Further, the electric vehicle charging system 214 may include switchingcircuitry (not shown) for selectively connecting and disconnecting theelectric vehicle induction coil 216 to the electric vehicle powerconverter 238. Disconnecting the electric vehicle induction coil 216 maysuspend charging and also may adjust the “load” as “seen” by the basewireless charging system 102 a (acting as a transmitter), which may beused to “cloak” the electric vehicle charging system 114 (acting as thereceiver) from the base wireless charging system 102 a. The load changesmay be detected if the transmitter includes the load sensing circuit.Accordingly, the transmitter, such as a base wireless charging system202, may have a mechanism for determining when receivers, such as anelectric vehicle charging system 114, are present in the near-field ofthe base system induction coil 204.

As described above, in operation, assuming energy transfer towards thevehicle or battery, input power is provided from the power supply 208such that the base system induction coil 204 generates a field forproviding the energy transfer. The electric vehicle induction coil 216couples to the radiated field and generates output power for storage orconsumption by the electric vehicle 112. As described above, in someembodiments, the base system induction coil 204 and electric vehicleinduction coil 116 are configured according to a mutual resonantrelationship such that the resonant frequency of the electric vehicleinduction coil 116 and the resonant frequency of the base systeminduction coil 204 are very close or substantially the same.Transmission losses between the base wireless power charging system 202and electric vehicle charging system 214 are minimal when the electricvehicle induction coil 216 is located in the near-field of the basesystem induction coil 204.

As stated, an efficient energy transfer occurs by coupling a largeportion of the energy in the near field of a transmitting induction coilto a receiving induction coil rather than propagating most of the energyin an electromagnetic wave to the far-field. When in the near field, acoupling mode may be established between the transmit induction coil andthe receive induction coil. The area around the induction coils wherethis near field coupling may occur is referred to herein as a near fieldcoupling mode region.

While not shown, the base charging system power converter 236 and theelectric vehicle power converter 238 may both include an oscillator, adriver circuit such as a power amplifier, a filter, and a matchingcircuit for efficient coupling with the wireless power induction coil.The oscillator may be configured to generate a desired frequency, whichmay be adjusted in response to an adjustment signal. The oscillatorsignal may be amplified by a power amplifier with an amplificationamount responsive to control signals. The filter and matching circuitmay be included to filter out harmonics or other unwanted frequenciesand match the impedance of the power conversion module to the wirelesspower induction coil. The power converters 236 and 238 may also includea rectifier and switching circuitry to generate a suitable power outputto charge the battery.

The electric vehicle induction coil 216 and base system induction coil204 as described throughout the disclosed embodiments may be referred toor configured as “loop” antennas, and more specifically, multi-turn loopantennas. The induction coils 204 and 216 may also be referred to hereinor be configured as “magnetic” antennas. The term “coils” is intended torefer to a component that may wirelessly output or receive energy fourcoupling to another “coil.” The coil may also be referred to as an“antenna” of a type that is configured to wirelessly output or receivepower. As used herein, coils 204 and 216 are examples of “power transfercomponents” of a type that are configured to wirelessly output,wirelessly receive, and/or wirelessly relay power. Loop (e.g.,multi-turn loop) antennas may be configured to include an air core or aphysical core such as a ferrite core. An air core loop antenna may allowthe placement of other components within the core area. Physical coreantennas including ferromagnetic or ferromagnetic materials may allowdevelopment of a stronger electromagnetic field and improved coupling.

As discussed above, efficient transfer of energy between a transmitterand receiver occurs during matched or nearly matched resonance between atransmitter and a receiver. However, even when resonance between atransmitter and receiver are not matched, energy may be transferred at alower efficiency. Transfer of energy occurs by coupling energy from thenear field of the transmitting induction coil to the receiving inductioncoil residing within a region (e.g., within a predetermined frequencyrange of the resonant frequency, or within a predetermined distance ofthe near-field region) where this near field is established rather thanpropagating the energy from the transmitting induction coil into freespace.

A resonant frequency may be based on the inductance and capacitance of atransmit circuit including an induction coil (e.g., the base systeminduction coil 204) as described above. As shown in FIG. 2, inductancemay generally be the inductance of the induction coil, whereas,capacitance may be added to the induction coil to create a resonantstructure at a desired resonant frequency. As a non-limiting example, asshown in FIG. 2, a capacitor may be added in series with the inductioncoil to create a resonant circuit (e.g., the base system transmitcircuit 206) that generates an electromagnetic field. Accordingly, forlarger diameter induction coils, the value of capacitance needed toinduce resonance may decrease as the diameter or inductance of the coilincreases. Inductance may also depend on a number of turns of aninduction coil. Furthermore, as the diameter of the induction coilincreases, the efficient energy transfer area of the near field mayincrease. Other resonant circuits are possible. As another non limitingexample, a capacitor may be placed in parallel between the two terminalsof the induction coil (e.g., a parallel resonant circuit). Furthermorean induction coil may be designed to have a high quality (Q) factor toimprove the resonance of the induction coil. For example, the Q factormay be 300 or greater.

As described above, according to some embodiments, coupling powerbetween two induction coils that are in the near field of one another isdisclosed. As described above, the near field may correspond to a regionaround the induction coil in which electromagnetic fields exist but maynot propagate or radiate away from the induction coil. Near-fieldcoupling-mode regions may correspond to a volume that is near thephysical volume of the induction coil, typically within a small fractionof the wavelength. According to some embodiments, electromagneticinduction coils, such as single and multi turn loop antennas, are usedfor both transmitting and receiving since magnetic near field amplitudesin practical embodiments tend to be higher for magnetic type coils incomparison to the electric near fields of an electric type antenna(e.g., a small dipole). This allows for potentially higher couplingbetween the pair. Furthermore, “electric” antennas (e.g., dipoles andmonopoles) or a combination of magnetic and electric antennas may beused.

FIG. 3 is another functional block diagram showing exemplary core andancillary components of the wireless power transfer system 100 ofFIG. 1. The wireless power transfer system 300 illustrates acommunication link 376, a guidance link 366, and alignment systems 352,354 for the base system induction coil 304 and electric vehicleinduction coil 316. As described above with reference to FIG. 2, andassuming energy flow towards the electric vehicle 112, in FIG. 3 a basecharging system power interface 360 may be configured to provide powerto a charging system power converter 336 from a power source, such as anAC or DC power supply 126. The base charging system power converter 336may receive AC or DC power from the base charging system power interface360 to excite the base system induction coil 304 at or near its resonantfrequency. The electric vehicle induction coil 316, when in the nearfield coupling-mode region, may receive energy from the near fieldcoupling mode region to oscillate at or near the resonant frequency. Theelectric vehicle power converter 338 converts the oscillating signalfrom the electric vehicle induction coil 316 to a power signal suitablefor charging a battery via the electric vehicle power interface.

The base wireless charging system 302 includes a base charging systemcontroller 342 and the electric vehicle charging system 314 includes anelectric vehicle controller 344. The base charging system controller 342may include a base charging system communication interface to othersystems (not shown) such as, for example, a computer, a wireless device,and a power distribution center, or a smart power grid. The electricvehicle controller 344 may include an electric vehicle communicationinterface to other systems (not shown) such as, for example, an on-boardcomputer on the vehicle, other battery charging controller, otherelectronic systems within the vehicles, and remote electronic systems.

The base charging system controller 342 and electric vehicle controller344 may include subsystems or modules for specific application withseparate communication channels. These communications channels may beseparate physical channels or separate logical channels. As non-limitingexamples, a base charging alignment system 352 may communicate with anelectric vehicle alignment system 354 through a communication link 356to provide a feedback mechanism for more closely aligning the basesystem induction coil 304 and electric vehicle induction coil 316,either autonomously or with operator assistance. Similarly, a basecharging guidance system 362 may communicate with an electric vehicleguidance system 364 through a guidance link 366 to provide a feedbackmechanism to guide an operator in aligning the base system inductioncoil 304 and electric vehicle induction coil 316. In addition, there maybe separate general-purpose communication links (e.g., channels), suchas communication link 376, supported by base charging communicationsystem 372 and electric vehicle communication system 374 forcommunicating other information between the base wireless power chargingsystem 302 and the electric vehicle charging system 314. Thisinformation may include information about electric vehiclecharacteristics, battery characteristics, charging status, and powercapabilities of both the base wireless power charging system 302 and theelectric vehicle charging system 314, as well as maintenance anddiagnostic data for the electric vehicle 112. These communication linksor channels may be separate physical communication channels such as, forexample, Dedicated Short-Range Communications (DSRC), IEEE 802.11 (e.g.,WiFi), Bluetooth, zigbee, cellular, etc.

Electric vehicle controller 344 may also include a battery managementsystem (BMS) (not shown) that manages charge and discharge of theelectric vehicle principal battery, a parking assistance system based onmicrowave or ultrasonic radar principles, a brake system configured toperform a semi-automatic parking operation, and a steering wheel servosystem configured to assist with a largely automated parking ‘park bywire’ that may provide higher parking accuracy, thus reducing the needfor mechanical horizontal induction coil alignment in any of the basewireless charging system 102 a and the electric vehicle charging system114. Further, electric vehicle controller 344 may be configured tocommunicate with electronics of the electric vehicle 112. For example,electric vehicle controller 344 may be configured to communicate withvisual output devices (e.g., a dashboard display), acoustic/audio outputdevices (e.g., buzzer, speakers), mechanical input devices (e.g.,keyboard, touch screen, and pointing devices such as joystick,trackball, etc.), and audio input devices (e.g., microphone withelectronic voice recognition).

Furthermore, the wireless power transfer system 300 may includedetection and sensor systems. For example, the wireless power transfersystem 300 may include sensors for use with systems to properly guidethe driver or the vehicle to the charging spot, sensors to mutuallyalign the induction coils with the required separation/coupling, sensorsto detect objects that may obstruct the electric vehicle induction coil316 from moving to a particular height and/or position to achievecoupling, and safety sensors for use with systems to perform a reliable,damage free, and safe operation of the system. For example, a safetysensor may include a sensor for detection of presence of animals orchildren approaching the wireless power induction coils 104 a, 116beyond a safety radius, detection of metal objects near the base systeminduction coil 304 that may be heated up (induction heating), detectionof hazardous events such as incandescent objects on the base systeminduction coil 304, and temperature monitoring of the base wirelesspower charging system 302 and electric vehicle charging system 314components.

The wireless power transfer system 300 may also support plug-in chargingvia a wired connection. A wired charge port may integrate the outputs ofthe two different chargers prior to transferring power to or from theelectric vehicle 112. Switching circuits may provide the functionalityas needed to support both wireless charging and charging via a wiredcharge port.

To communicate between a base wireless charging system 302 and anelectric vehicle charging system 314, the wireless power transfer system300 may use both in-band signaling and an RF data modem (e.g., Ethernetover radio in an unlicensed band). The out-of-band communication mayprovide sufficient bandwidth for the allocation of value-added servicesto the vehicle user/owner. A low depth amplitude or phase modulation ofthe wireless power carrier may serve as an in-band signaling system withminimal interference.

In addition, some communication may be performed via the wireless powerlink without using specific communications antennas. For example, thewireless power induction coils 304 and 316 may also be configured to actas wireless communication transmitters. Thus, some embodiments of thebase wireless power charging system 302 may include a controller (notshown) for enabling keying type protocol on the wireless power path. Bykeying the transmit power level (amplitude shift keying) at predefinedintervals with a predefined protocol, the receiver may detect a serialcommunication from the transmitter. The base charging system powerconverter 336 may include a load sensing circuit (not shown) fordetecting the presence or absence of active electric vehicle receiversin the vicinity of the near field generated by the base system inductioncoil 304. By way of example, a load sensing circuit monitors the currentflowing to the power amplifier, which is affected by the presence orabsence of active receivers in the vicinity of the near field generatedby base system induction coil 104 a. Detection of changes to the loadingon the power amplifier may be monitored by the base charging systemcontroller 342 for use in determining whether to enable the oscillatorfor transmitting energy, to communicate with an active receiver, or acombination thereof.

To enable wireless high power transfer, some embodiments may beconfigured to transfer power at a frequency in the range from 10-60 kHz.This low frequency coupling may allow highly efficient power conversionthat may be achieved using solid state devices. In addition, there maybe less coexistence issues with radio systems compared to other bands.

The wireless power transfer system 100 described may be used with avariety of electric vehicles 102 including rechargeable or replaceablebatteries.

FIG. 4 is a functional block diagram showing a replaceable contactlessbattery disposed in an electric vehicle 412, in accordance with anexemplary embodiment of the invention. In this embodiment, the lowbattery position may be useful for an electric vehicle battery unit thatintegrates a wireless power interface (e.g., a charger-to-batterycordless interface 426) and that may receive power from a charger (notshown) embedded in the ground. In FIG. 4, the electric vehicle batteryunit may be a rechargeable battery unit, and may be accommodated in abattery compartment 424. The electric vehicle battery unit also providesa wireless power interface 426, which may integrate the entire electricvehicle wireless power subsystem including a resonant induction coil,power conversion circuitry, and other control and communicationsfunctions as needed for efficient and safe wireless energy transferbetween a ground-based wireless charging unit and the electric vehiclebattery unit.

It may be useful for the electric vehicle induction coil to beintegrated flush with a bottom side of electric vehicle battery unit orthe vehicle body so that there are no protrusive parts and so that thespecified ground-to-vehicle body clearance may be maintained. Thisconfiguration may require some room in the electric vehicle battery unitdedicated to the electric vehicle wireless power subsystem. The electricvehicle battery unit 422 may also include a battery-to-EV cordlessinterface 422, and a charger-to-battery cordless interface 426 thatprovides contactless power and communication between the electricvehicle 412 and a base wireless charging system 102 a as shown in FIG.1.

In some embodiments, and with reference to FIG. 1, the base systeminduction coil 104 a and the electric vehicle induction coil 116 may bein a fixed position and the induction coils are brought within anear-field coupling region by overall placement of the electric vehicleinduction coil 116 relative to the base wireless charging system 102 a.However, in order to perform energy transfer rapidly, efficiently, andsafely, the distance between the base system induction coil 104 a andthe electric vehicle induction coil 116 may need to be reduced toimprove coupling. Thus, in some embodiments, the base system inductioncoil 104 a and/or the electric vehicle induction coil 116 may bedeployable and/or moveable to bring them into better alignment.

FIGS. 5A, 5B, 5C, and 5D are diagrams of exemplary configurations forthe placement of an induction coil and ferrite material relative to abattery, in accordance with exemplary embodiments of the invention. FIG.5A shows a fully ferrite embedded induction coil 536 a. The wirelesspower induction coil may include a ferrite material 538 a and a coil 536a wound about the ferrite material 538 a. The coil 536 a itself may bemade of stranded Litz wire. A conductive shield layer 532 a may beprovided to protect passengers of the vehicle from excessive EMFtransmission. Conductive shielding may be particularly useful invehicles made of plastic or composites.

FIG. 5B shows an optimally dimensioned ferrite plate (i.e., ferritebacking) to enhance coupling and to reduce eddy currents (heatdissipation) in the conductive shield 532 b. The coil 536 b may be fullyembedded in a non-conducting non-magnetic (e.g., plastic) material. Forexample, as illustrated in FIG. 5A-5D, the coil 536 b may be embedded ina protective housing 534 b. There may be a separation between the coil536 b and the ferrite material 538 b as the result of a trade-offbetween magnetic coupling and ferrite hysteresis losses.

FIG. 5C illustrates another embodiment where the coil 536 c (e.g., acopper Litz wire multi-turn coil) may be movable in a lateral (“X”)direction. FIG. 5D illustrates another embodiment where the inductioncoil module is deployed in a downward direction. In some embodiments,the battery unit includes one of a deployable and non-deployableelectric vehicle induction coil module 542 d as part of the wirelesspower interface. To prevent magnetic fields from penetrating into thebattery space 530 d and into the interior of the vehicle, there may be aconductive layer shield 532 d (e.g., a copper sheet) between the batteryspace 530 d and the vehicle. Furthermore, a non-conductive (e.g.,plastic) protective layer 534 d may be used to protect the conductivelayer shield 532 d, the coil 536 d, and the ferrite material 538 d fromenvironmental impacts (e.g., mechanical damage, oxidization, etc.).Furthermore, the coil 536 d may be movable in lateral X and/or Ydirections. FIG. 5D illustrates an embodiment wherein the electricvehicle induction coil module 540 d is deployed in a downward Zdirection relative to a battery unit body.

The design of this deployable electric vehicle induction coil module 542d is similar to that of FIG. 5B except there is no conductive shieldingat the electric vehicle induction coil module 542 d. The conductiveshield 532 d stays with the battery unit body. The protective layer 534d (e.g., plastic layer) is provided between the conductive shield 532 dand the electric vehicle induction coil module 542 d when the electricvehicle induction coil module 542 d is not in a deployed state. Thephysical separation of the electric vehicle induction coil module 542 dfrom the battery unit body may have a positive effect on the inductioncoil's performance.

As discussed above, the electric vehicle induction coil module 542 dthat is deployed may contain only the coil 536 d (e.g., Litz wire) andferrite material 538 d. Ferrite backing may be provided to enhancecoupling and to prevent from excessive eddy current losses in avehicle's underbody or in the conductive layer shield 532 d. Moreover,the electric vehicle induction coil module 542 d may include a flexiblewire connection to power conversion electronics and sensor electronics.This wire bundle may be integrated into the mechanical gear fordeploying the electric vehicle induction coil module 542 d.

With reference to FIG. 1, the charging systems described above may beused in a variety of locations for charging an electric vehicle 112, ortransferring power back to a power grid. For example, the transfer ofpower may occur in a parking lot environment. It is noted that a“parking area” may also be referred to herein as a “parking space.” Toenhance the efficiency of a vehicle wireless power transfer system 100,an electric vehicle 112 may be aligned along an X direction and a Ydirection to enable an electric vehicle induction coil 116 within theelectric vehicle 112 to be adequately aligned with a base wirelesscharging system 102 a within an associated parking area.

Furthermore, the disclosed embodiments are applicable to parking lotshaving one or more parking spaces or parking areas, wherein at least oneparking space within a parking lot may comprise a base wireless chargingsystem 102 a. Guidance systems (not shown) may be used to assist avehicle operator in positioning an electric vehicle 112 in a parkingarea to align an electric vehicle induction coil 116 within the electricvehicle 112 with a base wireless charging system 102 a. Guidance systemsmay include electronic based approaches (e.g., radio positioning,direction finding principles, and/or optical, quasi-optical and/orultrasonic sensing methods) or mechanical-based approaches (e.g.,vehicle wheel guides, tracks or stops), or any combination thereof, forassisting an electric vehicle operator in positioning an electricvehicle 112 to enable an induction coil 116 within the electric vehicle112 to be adequately aligned with a charging induction coil within acharging base (e.g., base wireless charging system 102 a). For example,the guidance system may present the vehicle operator with informationhelpful in positioning the electric vehicle 112 (e.g., by presentingsigns, directions, or other information to the vehicle operator, forexample, by augmented reality displayed in the driver's cockpit). Thisinformation can include information (e.g., a driving angle, a distancevalue) derived from a beacon guidance subsystem (e.g., magnetic orelectromagnetic).

As discussed above, the electric vehicle charging system 114 may beplaced on the underside of the electric vehicle 112 for transmitting andreceiving power from a base wireless charging system 102 a. For example,an electric vehicle induction coil 116 may be integrated into thevehicles underbody preferably near a center position providing maximumsafety distance in regards to EM exposure and permitting forward andreverse parking of the electric vehicle.

FIG. 6 is a chart of a frequency spectrum showing exemplary frequenciesthat may be used for wireless charging an electric vehicle, inaccordance with an exemplary embodiment of the invention. As shown inFIG. 6, potential frequency ranges for wireless high power transfer toelectric vehicles may include: VLF in a 3 kHz to 30 kHz band, lower LFin a 30 kHz to 150 kHz band (for ISM-like applications) with someexclusions, HF 6.78 MHz (ITU-R ISM-Band 6.765-6.795 MHz), HF 13.56 MHz(ITU-R ISM-Band 13.553-13.567), and HF 27.12 MHz (ITU-R ISM-Band26.957-27.283).

FIG. 7 is a chart showing exemplary frequencies and transmissiondistances that may be useful in wireless charging electric vehicles, inaccordance with an exemplary embodiment of the invention. Some exampletransmission distances that may be useful for electric vehicle wirelesscharging are about 30 mm, about 75 mm, and about 150 mm. Some exemplaryfrequencies may be about 27 kHz in the VLF band and about 135 kHz in theLF band.

During a charging cycle of an electric vehicle, a Base Charging Unit(BCU) of the wireless power transfer system may go through variousstates of operation. The wireless power transfer system may be referredto as a “charging system.” The BCU may include the base wirelesscharging system 102 a and/or 102 b of FIG. 1. The BCU may also include acontroller and/or a power conversion unit, such as power converter 236as illustrated in FIG. 2. Further, the BCU may include one or more basecharging pads that include an induction coil, such as induction coils104 a and 104 b as illustrated in FIG. 1. As the BCU goes through thevarious states, the BCU interacts with a charging station. The chargingstation may include the local distribution center 130, as illustrated inFIG. 1, and may further include a controller, a graphical userinterface, a communications module, and a network connection to a remoteserver or group of servers.

With reference to FIG. 1, the charging systems described above may beused in a variety of locations for charging an electric vehicle 112, ortransferring power back to a power grid. For example, the transfer ofpower may occur in a parking lot environment. It is noted that a“parking area” may also be referred to herein as a “parking space.” Toenhance the efficiency of a vehicle wireless power transfer system 100,an electric vehicle 112 may be aligned (e.g., using a sense current)along an X direction and a Y direction to enable an electric vehicleinduction coil 116 within the electric vehicle 112 to be adequatelyaligned with a base wireless charging system 102 a within an associatedparking area.

Furthermore, the disclosed embodiments are applicable to parking lotshaving one or more parking spaces or parking areas, wherein at least oneparking space within a parking lot may comprise a base wireless chargingsystem 102 a. Guidance systems (such as the guidance systems 362 and364, described above with respect to FIG. 3) may be used to assist avehicle operator in positioning an electric vehicle 112 in a parkingarea to align an electric vehicle induction coil 116 within the electricvehicle 112 with a base wireless charging system 102 a. Guidance systemsmay include electronic based approaches (e.g., radio positioning,direction finding principles, and/or optical, quasi-optical and/orultrasonic sensing methods) or mechanical-based approaches (e.g.,vehicle wheel guides, tracks or stops), or any combination thereof, forassisting an electric vehicle operator in positioning an electricvehicle 112 to enable an induction coil 116 within the electric vehicle112 to be adequately aligned with a charging induction coil within acharging base (e.g., base wireless charging system 102 a). For example,the guidance system may present the vehicle operator with informationhelpful in positioning the electric vehicle 112 (e.g., by presentingsigns, directions, or other information to the vehicle operator, forexample, by augmented reality displayed in the driver's cockpit). Thisinformation can include information (e.g., a driving angle, a distancevalue) derived from a beacon guidance subsystem (e.g., magnetic orelectromagnetic).

FIG. 8A is a functional block diagram of an example multi-vehicle andmulti-parking parking and charging system 800, in accordance withvarious implementations. The components illustrated in FIG. 8A may beused in the wireless power transfer system 100 of FIG. 1, in accordancewith various embodiments. In one embodiment, the parking and chargingsystem 800 may include a plurality of charging stations 801 a-c, eachcorresponding to one of a plurality of parking spaces 806 a-c, thatallow the system 800 to simultaneously charge a plurality of vehicles,such as an electric vehicle 808. In some embodiments, each chargingstation 801 a-c may include a Base Controller Unit (BCU) (e.g., BCUs 804a-c), a base pad (e.g., base pads 802 a-c), and a transmitter 803 (e.g.,transmitters 803 a-c).

The transmitter 803 can be configured to transmit BCU identification toa vehicle 808 (e.g., received by a receiver 812 of the vehicle 808) thatis in a range of reception when the vehicle 808 is in a locationcompatible with charging the vehicle 808 using the BCU corresponding tothe transmitter 803. For example, the transmitters 803 a-c can eachtransmit a signal (e.g., a beacon signal) comprising the BCUidentification and configured to be received by the receiver 812 of thevehicle 808. In some aspects, the transmitters 803 a-c may be configuredsuch that the charging station identifier transmitted by a firsttransmitter 803 a can only be received by a vehicle 808 that ispositioned substantially within a parking space in which the transmitter803 a is positioned. For example, a vehicle 808 that is positionedsubstantially within a parking space in which charging station 801 a ispositioned may only be able to receive the charging station identifierfrom transmitter 803 a but may not be able to receive the chargingstation identifiers for charging stations 801 b and 801 c. In anon-limiting example, the strength of the transmitted signal from thetransmitter 803 a may be at a level sufficient for successfultransmission of the charging station identifier to a vehicle 808 locatedin a single parking space. In other aspects, a vehicle 808 may be ableto receive transmissions from multiple adjacent charging stations 801 a,801 b, and 801 c, but the vehicle 808 is configured to specificallyidentify the charging station 801 a, 801 b, or 801 c from which atransmission originates based on one or more characteristics of thetransmission (e.g., based on signal strength or based on being able todetermine a directional component of the transmission). This may enablethe vehicle 808 to be able to determine the charging station identifierfrom the transmission of the particular charging station 801 a, 801 b,or 801 c that the vehicle 808 is being positioned to wirelessly receivepower from. Various communication formats (e.g., RFID, Bluetooth LE, ashort range proximity detection technology) are compatible with use forthe transmitters 803 a-c and receiver 812 in accordance with certainembodiments described herein. This communication channel between theBCUs 804 a-c and the vehicle 808 can be considered to be a type ofproximity detector in one aspect. In certain embodiments in which theBCU 804 also receives information directly from the vehicle 808,appropriate transceivers can be used in place of the transmitters 803and the receiver 812.

In accordance with an embodiment, the charging stations 801 a-c maycommunicate with a communication hub, e.g., a base common communication(BCC) system 815 configured to communicate with each of the basecharging stations 801 a-c and configured to communicate with one or moreparking and charging backend servers 814 via a network 816. The network816 may be any type of communication network such as, for example, theInternet, a wide area network (WAN), a wireless local area network(WLAN), etc. Various communication formats (e.g., HomePlug, Ethernet,RS-485, CAN) are compatible for communication between the BCC system 815and the BCUs 804 a-c in accordance with certain embodiments describedherein. The communication hub can be either separate from the pluralityof charging stations 801 a-c or can be part of the plurality of chargingstations 801 a-c.

The BCC 815 can comprise a receiver 817 configured to communicate with atransmitter 819 of the vehicle 808, as described more fully below.Various communication formats (e.g., DSRC, Bluetooth LE, WiFi) arecompatible for communication between the BCC system 815 and the vehicle808 (via the receiver 817 and the transmitter 819) in accordance withcertain embodiments described herein. In certain embodiments in whichthe BCC 815 also transmits information to the vehicle 808, anappropriate transceiver can be used in place of the receiver 817 and anappropriate transceiver can be used in place of the transmitter 819.

In some embodiments, each charging station 801 a-c can correspond to thebase wireless charging system 302, discussed above with respect to FIG.3. For example, the BCUs 801 a-c can correspond to the base chargingsystem controller 342, the base pads 802 a-c can correspond to the basesystem induction coil 304, and each charging station 801 a-c can includethe base charging communication system 372. In other embodiments, thecharging system 800 may include one or more base wireless chargingsystems 302, which can each include a plurality of each system componentsuch as the base charging system controller 342, and the base systeminduction coil 304. In various embodiments, the transmitters 803 a-c canbe placed curbside, on the ground next to the base pads 802 a-c, and/orintegrated directly into the base bad 802 a. The charging stations 801a-c can include multiple transmitters.

In some embodiments, the plurality of parking spaces 806 a-c are eachmarked with a space indicator, such as a letter or a number. Forexample, a sign of a charging station may be provided on the parkingspace so as to allow a driver to identify the corresponding chargingstation 801. As shown in FIG. 8A, the parking space 806 a, correspondingto the charging station 801 a, the BCU 804 a, and the base pad 802 a,may be marked with a space indicator “A.” The parking space 806 b,corresponding to the charging station 801 b, the BCU 804 b, and the basepad 802 b, may be marked with a space indicator “B.” The parking space806 c, corresponding to the charging station 801 c, the BCU 804 c, andthe base pad 802 c, may be marked with a space indicator “C.” The spaceindicators may assist a user to identify available charging stations 801a-c in the parking and charging system 800.

The electric vehicle 808 may include a Vehicle Controller Unit (VCU)810, a receiver 812, and a transmitter 819. In an embodiment, theelectric vehicle 808 can be the vehicle 112 (FIG. 1). The electricvehicle 808 can include the electric vehicle charging system 314,described above with respect to FIG. 3. For example, the VCU 810 cancorrespond to the electric vehicle controller 344, and the electricvehicle 808 can include the electric vehicle communication system 374.The electric vehicle 808 may include multiple receivers, transmitters,and/or transceivers.

The electric vehicle communication system 374 may be used to communicatewith one or more of a plurality of base charging communication systems372 located within each of the charging stations 801 a-c in the parkingand charging system 800. As discussed above, with respect to FIG. 3, theelectric vehicle communication system 374 can communicate with the basecharging communication system 372 by any wireless communication systemsuch as Dedicated Short-Range Communications (DSRC), IEEE 802.11 (e.g.,WiFi), Bluetooth, zigbee, cellular, etc. Accordingly, in someembodiments, the electric vehicle communication system 374 can act as abase station to which the base charging communication system 372 canconnect. In other embodiments, each base charging communication system372 can act as a base station to which the electric vehiclecommunication system 374 can connect.

FIG. 8B schematically illustrates an example configuration withcommunication between the BCC 815, the BCUs 804, and the vehicle 808 inaccordance with certain embodiments described herein. Prior to theelectric vehicle 808 (e.g., vehicle 808 a) being positioned over aparking spot (e.g., while or upon entering the parking and chargingsystem 800 with the plurality of BCUs 804 a-c), a first communicationlink (denoted by diamonds labeled “1” in FIG. 8B) can be establishedbetween the vehicle 808 and the BCC 815 (e.g., using transmitter 819 andreceiver 817). The vehicle 808 can transmit at least one first signal tothe BCC 815 via the first communication link (e.g., while the vehicle808 a is a first distance from at least one charging station 801). Theat least one first signal can comprise information, examples of whichinclude but are not limited to, the vehicle identification, vehiclecharacteristics, driver information, information regarding the paymentmethod expected to be used, or other information that may be helpful inassigning, scheduling, or reserving one of the BCUs 804 for charging ofthe vehicle 808.

In certain embodiments, the BCC 815 can also transmit information (e.g.,by transmitting at least one third signal) to the vehicle 808 via thefirst communication link (e.g., in configurations in which transceiversare used in place of transmitter 819 and receiver 817). Informationtransmitted by the BCC 815 to the vehicle 808 can include but are notlimited to, the number of BCUs 804 which are available for charging thevehicle 808, the identities of the BCUs 804 which are available forcharging the vehicle 808, a schedule of costs for charging, a chargingmenu of options available for charging the vehicle 808 using theavailable BCUs 804, and other information that may be helpful inassigning, scheduling, or reserving one of the BCUs 804 for charging ofthe vehicle 808. For example, prior to the electric vehicle 808 enteringthe parking and charging system 800, the BCC 815 can inform the vehicle808 that BCUs 804 b, 804 c are available (with the parking space for BCU804 a being occupied by another vehicle 808 b). Upon the assignment,schedule, or reservation being made to charge the vehicle 808, the BCC815 can transmit information to the vehicle 808 via the firstcommunication link regarding the identity of the one or more BCUs 804available to charge the vehicle 808 (e.g., the identity of the one BCU804 assigned, scheduled, or reserved for charging the vehicle 808).

The BCC 815 can also communicate with the various BCUs 804 (e.g., via awired connection, denoted by diamonds labeled “2” in FIG. 8B). Forexample, the BCC 815 can communicate with the BCUs 804 a-c to find outwhich of the BCUs 804 a-c are available for charging the vehicle 808. Incertain embodiments, upon the assignment, schedule, or reservation forcharging of the vehicle 808, the BCC 815 can transmit information to theone or more BCUs 804 available for charging of the vehicle 808 (e.g.,the identity of the vehicle 808 to be charged).

In certain embodiments, the BCC 815 can keep track of which BCUs 804 arecurrently unavailable for charging an incoming vehicle 808. For example,the BCC 815 can keep track of which BCUs 804 are being used to chargeanother vehicle (e.g., BCU 804 a being used to charge vehicle 808 b inFIG. 8B). In certain embodiments, non-electric vehicles may also beparked over one or more of the BCUs 804 such that these BCUs 804 arealso not available for charging the vehicle 808, even though they arenot currently being used to charge a vehicle 808. In certain suchembodiments, the BCUs 804 are configured to detect whether there is anon-electric vehicle parked at (e.g., over) the BCU 804. For example,the BCU 804 can be configured to periodically or intermittently inject alow current into the charging pad 802 and to measure an inductancechange due to a large metallic object over the charging pad 802. Upondetecting an inductance change indicative of a non-electric vehicle, theBCU 804 can communicate to the BCC 815 that the BCU 804 is unavailablefor charging the vehicle 808 (e.g., marking the BCU 804 as beingunavailable for charging electric vehicles).

When the electric vehicle 808 enters the parking and charging system 800with the plurality of available charging stations 801 a-c, a driver ofthe vehicle 808 is able to identify one or more of the charging stations801 (e.g., the charging station 801 comprising the BCU 804 scheduled tocharge the vehicle 808). In one embodiment, the driver of a vehicle 808may visually identify the parking spaces 806 using, for example, thespace indicators as described above. Thus, a driver of the vehicle 808may navigate within the parking facility to find the available (e.g.,assigned, scheduled, or reserved) charging station 801 for providingenergy to charge the electric vehicle 808. As described above, the BCC815 may communicate to the vehicle 808 a specific charging station 804that the charging system 808 has reserved for the vehicle 808. Theinformation regarding the charging station 804 may be provided to theuser via a user interface. When the vehicle 808 approaches the parkingspace 806, or once the vehicle 808 is parked in the parking space 806,the charging station 801 may attempt to pair with the vehicle 808 whichis now within communication range.

The transmitter 803 of the charging station 801 can be configured totransmit at least one second signal (e.g., a beacon signal) via a secondcommunication link (e.g., while the vehicle 808 is a second distancefrom the at least one charging station 801, with the second distanceless than the first distance). The at least one second signal cancomprise an identification of the BCU 804, and the receiver 812 of theelectric vehicle 808 can be configured to receive the at least onesecond signal. Each base charging communication system 372 can act as abase station to which the electric vehicle communication system 374 canconnect. Each BCU 804 can have a globally or locally unique identifier(e.g., “BCU1”), which the base communication system 372 can broadcast.For example, in an embodiment using the DSRC standard, the base chargingcommunication system 372 can broadcast a WBSS ID of “BCU1.” Thetransmitter 803 of the charging station 801 can be configured toindicate the ID of the BCU 804, and/or the broadcast identifier (e.g.,“BCU1”). Accordingly, when the electric vehicle 808 enters a parkingspace such as the parking space 806 a, the receiver 812 on the vehicle808 can receive the identifier of the BCU 804.

Because the receiver 812 on the electric vehicle 808 can have a shortercommunication range than the electric vehicle communication system 374(e.g., the first communication link has a longer range than does thesecond communication link), the receiver 812 may only be capable ofreceiving the at least one second signal while in the parking space 806a. The VCU 810 can obtain the identifier of the BCU 804 a from thereceiver 812, and can cause the electric vehicle communication system374 to connect to the appropriate base charging communication system372. In certain embodiments, the charging station 801 can start a sensecurrent at the base pad 802 to be used to help align the electricvehicle 808 with the base pad 802 when the electric vehicle 808 receivesthe identification of the charging station 801 and connects via the basecharging communication system 372.

If the driver has positioned the vehicle 808 in proximity to a differentBCU 804 than one previously assigned, scheduled, or reserved forcharging the vehicle 808, the BCC 815 can reassign, reschedule, orre-reserve the BCU 804 in proximity to the vehicle 808 to charge thevehicle 808. If the driver has positioned the vehicle 808 between twoadjacent BCUs 804, the BCC 815 can make an appropriate assignment of oneof the two BCUs 804 to charge the vehicle 808 (e.g., the BCU 804 closestto the vehicle 808), even if this assignment comprises de-assigning thepreviously-scheduled BCU 804 in favor of the different BCU 804.

Once a communication link is established between the electric vehicle808 and the charging station 801 corresponding to appropriate parkingspace 806, the communication link can be used for one or more of:electric vehicle guidance, electric vehicle alignment, charging control,status communication, authorization, identification, payment management,etc.

FIG. 9A is an example state diagram for a vehicle in accordance withcertain embodiments described herein and FIGS. 9B-9E are example flowdiagrams corresponding to the various states. In a “disconnected” state(see, e.g., FIG. 9D), the vehicle 808 is not yet in communication withthe parking and charging system 800 and the vehicle 808 scans (e.g.,continuously, periodically, intermittently) for a BCC 815 with which tocommunicate. In a “connected” state (see, e.g., FIG. 9D), after havingdetected a BCC 815 with which to communicate, the vehicle 808 canestablish a communication channel (e.g., secure or unsecure) with theBCC 815, and can exchange appropriate information (e.g., vehicleidentification) with the BCC 815.

FIG. 9B is an example flowchart of the “detected” state in accordancewith certain embodiments described herein. In the “detected” state, thereceiver 812 of the vehicle 808 detects the signal from the transmitter803 of the BCU 804 so the vehicle 808 is in a location compatible withproceeding with the charging process. For example, the vehicle 808 canreceive a list of available BCUs 804 from the BCC 815 for charging thevehicle 808, and can scan for one of the available BCUs 804. Upondetecting an available BCU 804, the vehicle 808 can send the BCUidentification to the BCC 815, which then allocates the detected BCU 804to the charging of the vehicle 808, and enters the “start alignment”state. If an available BCU 804 is not detected, the vehicle 808 reentersthe “connected” state.

The receiver 812 of the vehicle 808 can continually, periodically, orintermittently scan for a BCU identification throughout the alignmentprocess and/or the charging process. If a new BCU identification isdetected (e.g., due to the vehicle 808 moving closer to anotheravailable BCU), then the vehicle 808 determines if the vehicle 808 isalready associated with another BCU. If not, then the vehicle 808 sendsthe BCU identification to the BCC 815, which then allocates the detectedBCU 804 to the charging of the vehicle 808, and enters the “startalignment” state. The allocation of the BCU 804 to the charging of thevehicle 808 can be performed by the vehicle 808, by the BCC 815, or byboth. If the vehicle 808 is already associated with another BCU 804,then the vehicle 808 determines if the BCU 804 is in an alignment mode,and if so the alignment mode is stopped. If the vehicle 808 detectsmultiple BCUs, then the vehicle 808 can determine the more optimal BCUto use (e.g., closest BCU) for charging, for example, based on thereceived signal strength indication (RSSI) and/or the time-of-flight andBCU readings. The determination of the more optimal BCU to use forcharging can be performed by the vehicle 808, by the BCC 815, or byboth. The vehicle 808 can then disconnect from the less optimal BCU andcan send the identification of the more optimal BCU to the BCC forallocation to the charging process. After allocating a BCU to thecharging process, an alignment process is begun.

FIG. 9C is an example flowchart of the “aligning” state in accordancewith certain embodiments described herein. In the “aligning” state, thealignment process proceeds to align the charging pad 802 with the coilsof the VCU 810 of the vehicle 808, with a score or other measure of thedegree of alignment being checked (e.g., continually, periodically,intermittently) to determine if the desired level of alignment isachieved. For example, if the alignment score is greater than or equalto a predetermined level, then the charging pad 802 and the VCU 810 aredeemed to be aligned, and the vehicle 808 enters the “aligned/ready”state. The “aligned/ready” state (see, e.g., FIG. 9D) is the restingstate after completed alignment, until user action or vehicle action tostart charging is received.

Once user action or vehicle action to start charging is received, thevehicle 808 is in a “prepare to charge” state (see, e.g., FIG. 9E) inwhich the alignment is validated. If valid alignment, the chargingprocess proceeds, and if not valid alignment, the vehicle reenters the“aligning” state.

In the “charging” state (see, e.g., FIG. 9E), dynamic vehicle chargingparameters are sent to the BCU and the charging process proceeds tocharge the vehicle 808. In a “charging stopped/complete” state (see,e.g., FIG. 9E), the charging process has been halted, either because ofa detected fault condition or because the vehicle 808 is fully charged.If the charging process was halted due to a detected fault condition,the charging process can restart once the fault condition is resolved.For example, if the fault condition is that alignment was insufficientto proceed with the charging process, the vehicle 808 can be placedagain in the “aligning” state.

FIG. 10 is an example flow diagram for the communications between thevehicle 808 and the BCC 815 in accordance with certain embodimentsdescribed herein. The flow diagram of FIG. 10 can be applied to eachvehicle 808 that communicates with the BCC 815. Once a communicationchannel (e.g., secure or unsecure) is established between the vehicle808 and the BCC 815, the vehicle 808 can send information (e.g., avehicle identification, charging characteristics of the vehicle) to theBCC 815, and the vehicle 808 can be authorized to be charged by thecharging system 800. The BCC 815 can send to the vehicle 808 informationregarding the list of available charging spaces, the locations of suchavailable spaces, and the number of such available spaces. The BCC 815can also send the vehicle identification and/or other informationreceived from the vehicle 808 to the available BCUs 804.

Once in proximity to the BCU 804, the vehicle 808 can detect the signalfrom the transmitter 803 of the charging station 801 and can send thecharging pad identifier to the BCC 815, which then can reserve thedetected BCU for the vehicle identification of the vehicle 808. Afterinitiating and completing an alignment process to align the VCU 810 ofthe vehicle 808 with the charging pad of the BCU 804, the BCU 804 cansend the charger characteristics to the vehicle 808, and the chargingprocess can proceed. Once charging is completed and the vehicle 808 isdisconnected from the BCU 804 and the BCC 815, the BCC can remove theexisting reservation and mark the BCU 815 as being available again. Ifduring the process flow of FIG. 10, the vehicle 808 detects another BCUidentification, the BCC 815 can check to see if the vehicle 808 hasalready been assigned another charging space with another BCU 804 andwhether the alignment current is on. Depending on these conditions, theBCC 815 can change the BCU 804 which is reserved to the vehicle 808.

In certain embodiments, the BCU 804 can also detect the vehicleidentification and can measure the RSSI and/or the time-of-flight (e.g.,round-trip delay) of signals between the BCU 804 and the vehicle 808 todetermine which BCU 804 is closest to the vehicle 808, which can bedeemed to be the best BCU 804 for charging the vehicle 808. Thedetermination of the best BCU to use for charging can be performed bythe vehicle 808, by the BCC 815, or by both. In a similar manner to thetransmission by the BCU of its identification to the vehicle 808, thevehicle 808 of certain embodiments can transmit its identification tothe BCU. For example, the vehicle 808 can use an algorithm with rollingvehicle identification to deal with privacy issues. In certainembodiments, the electric vehicle 808 is configured to turn on and offthe transmitter 819 (e.g., automatically or by the driver) to avoidtransmitting the at least one first signal during times at which suchtransmission is not needed or is not desired (e.g., to protect privacy).

FIG. 11 is an example diagram of the signals sent among the vehicle 808,the BCC 815, and the BCUs 804 (e.g., BCU1, BCU2, BCU3) in an automaticcharging space selection process in accordance with certain embodimentsdescribed herein. In a connect state, the vehicle 808 can connect to theBCC 815 and transmit vehicle information to the BCC 815 (e.g., in atleast one first signal via a first communication link) (e.g., while thevehicle 808 is a first distance from at least one charging station 801).In a vehicle approach state, the BCC 815 can transmit informationregarding the approaching vehicle 808 to the BCUs 804. BCUs that are notidle (e.g., BCUs that are not available for charging the approachingvehicle 808; BCU1 and BCU2 in FIG. 11) can timeout and discard thevehicle information (e.g., vehicle identification) after a predeterminedperiod of time. In a BCU detection state, an idle BCU (e.g., BCU3) cantransmit its BCU identification (e.g., in at least one second signal viaa second communication link, such as a Bluetooth LE advertisement)(e.g., while the vehicle 808 is a second distance, that is less than thefirst distance, from the at least one charging station 801) to thevehicle 808, and the vehicle 808 can transmit the received BCUidentification to the BCC 815.

In a BCU-vehicle pairing state, the BCC 815 can reserve the BCU (e.g.,BCU3) for charging the vehicle 808 having the vehicle identificationthat was received in the connect state, and the BCC 815 can send acorresponding signal to the BCU (e.g., BCU3) which pairs the vehicleidentification with the BCU. In an alignment state, the vehicle 808 cansend a signal to the BCC 815, which sends a signal to the BCU 804,starting the alignment process, and the BCU 804 can respond bytransmitting an alignment current through its charging pad. Oncealignment has been completed, the vehicle 808 can send a signal to theBCC 815, which sends a signal to the BCU 804, stopping the alignmentprocess. In a charging state, the vehicle 808 can send a signal to theBCC 815, which sends a signal to the BCU 804, starting the chargingprocess, and the BCU 804 can respond by transmitting a charging currentthrough its charging pad. Once charging has been completed, the vehiclecan send a signal to the BCC 815, which sends a signal to the BCU 804,stopping the charging process. In a disconnect state, the vehicle 808disconnects from the BCC 815, and the BCC 815 notes that the BCU 804 isagain available for charging an incoming vehicle.

In accordance with certain embodiments above, the exchanges ofinformation may use two different channels for communications related todifferent purposes. Certain aspects of embodiments below are directed todifferent types of communication that may happen over different channelsin accordance the embodiments described above. While the embodimentsbelow may be described relative to the electric vehicle wirelesscharging system 114 and base wireless charging system 102 a of FIGS.1-3, the embodiments are applicable any of the configurations ofcommunication controllers described herein, particularly with referenceto FIGS. 8A and 8B, for example with respect to the descriptions of thecommunications between BCU 804 and VCU 810. For example, thecommunication controllers described below may be configured inaccordance with FIG. 8A in certain aspects.

The electric vehicle infrastructure communication interface may includetwo different channels (e.g., a first communication link and a secondcommunication link), that are configured to effectively manage thecharging process. In certain embodiments, a method is provided forcommunicating with a wireless electric vehicle charging system 800including a charging station 801 configured to charge an electricvehicle 808. The method includes establishing a first communicationslink between the electric vehicle 808 and a communications controller(e.g., BCC 815) of the charging system 800. The method includesexchanging, via the first communications link, one or more servicemessages with the communications controller (e.g., BCC 815) of thecharging system 800, the service messages indicative of at least one ofone or more capabilities of the electric vehicle 808 or charging system800, authorization, or authentication for wirelessly receiving powerfrom the charging station. The method further includes sending via thefirst communications link, in response to exchanging the one or moreservice messages, a guidance request message indicative of a request forguiding the electric vehicle 808 to the charging station 801. The methodfurther includes receiving one or more guidance beacons from thecharging station 801 for performing at least one of a guidance operationor an alignment operation with the charging station 801, the guidancebeacon forming at least in part a second communication channel. Themethod further includes extracting an identifier of the charging station801 from the guidance beacon. The method further includes sending amessage to the communications controller indicative of alignment betweenthe electric vehicle 808 and the charging station 801, the messagefurther comprising the identifier of the charging station 801 and anidentifier of the electric vehicle 808. The method further includessending a charging request message to the communications controller inresponse to sending the message indicative of alignment via the firstcommunications channel. Examples of guidance beacons compatible withcertain embodiments described herein include, but are not limited to,magnetic guidance beacons and electromagnetic guidance beacons.

In certain embodiments, the method further includes establishing thesecond communications link with the charging station 801, with thesecond communication link configured to communicate data via modulationof the wireless power field used for transferring power to the electricvehicle 808. The second communication link can be configured tocommunicate data via one of load modulation or angle modulation of thewireless power field used for transferring power to the electric vehicle808. In certain embodiments, the second communication link is configuredto communicate data relating to at least one of power control betweenthe electric vehicle 808 and the charging system 800, safety signaling,an identifier of the charging station, guidance information, oralignment information via one of load modulation or angle modulation.The second communication link can be configured to communicate viamodulation at or substantially at a frequency of the wireless powerfield. The second communication link can be configured to broadcast adevice identifier (ID) of the charging station via modulation of thewireless power field used for transferring power.

In certain embodiments, an apparatus is provided for wirelesslyreceiving power at an electric vehicle 808 from a charging station 801.The apparatus includes a wireless power receive circuit including apower transfer component configured to wirelessly receive power from thecharging station 801 at a level sufficient to charge a battery of anelectric vehicle. The apparatus further includes a communicationscontroller (e.g., VCU 810) operably connected with the wireless powerreceive circuit. The communications controller is configured toestablish a first communications link with a base communicationscontroller 815 of a charging system configured to control the chargingstation 801. The communications controller is further configured toexchange, via the first communications link, one or more servicemessages with the base communications controller 815 of the chargingsystem, the service messages indicative of at least one of one or morecapabilities of the electric vehicle 808 or charging system 800,authentication, or authorization for wirelessly receiving power from thecharging station 801. The communications controller is furtherconfigured to send via the first communications link, in response toexchanging the one or more service messages, a guidance request messageindicative of a request for guiding the electric vehicle 808 to thecharging station 801. The wireless power receive circuit is configuredto receive one or more guidance beacons from the charging station 801for performing at least one of a guidance operation or an alignmentoperation with the charging station 801, the guidance beacon forming atleast in part a second communication channel. The wireless power receivecircuit is configured to further extract an identifier of the chargingstation 801 from the guidance beacon. The communications controller isfurther configured to send a message to the base communicationscontroller 815 indicative of alignment between the electric vehicle 808and the charging station 801, the message further comprising theidentifier of the charging station 801 and an identifier of the electricvehicle 808. The communications controller is further configured to senda charging request message to the base communications controller 815 inresponse to sending the message indicative of alignment via the firstcommunications channel. Examples of guidance beacons compatible withcertain embodiments described herein include, but are not limited to,magnetic guidance beacons and electromagnetic guidance beacons.

In certain embodiments, an apparatus is provided for communicating witha wireless electric vehicle charging system 800 including a chargingstation 801 configured to charge an electric vehicle 808. The apparatusincludes means for establishing a first communications link between theelectric vehicle 808 and a communications controller of the chargingsystem 800. The apparatus further includes means for exchanging, via thefirst communications link, one or more service messages with thecommunications controller of the charging system 800, the servicemessages indicative of one or more capabilities of the electric vehicle808 or charging system 800, authorization, or authentication forwirelessly receiving power from the charging station 801. The apparatusfurther includes means for sending via the first communications link, inresponse to exchanging the one or more service messages, a guidancerequest message indicative of a request for guiding the electric vehicle808 to the charging station 801. The apparatus further includes meansfor receiving one or more guidance beacons from the charging station 801for performing at least one of a guidance operation or an alignmentoperation with the charging station 801, the guidance beacon forming atleast in part a second communication channel. The apparatus furtherincludes means for extracting an identifier of the charging station 801from the guidance beacon. The apparatus further includes means forsending a message to the communications controller indicative ofalignment between the electric vehicle 808 and the charging station 801,the message further comprising the identifier of the charging station801 and an identifier of the electric vehicle 808. The apparatus furtherincludes means for sending a charging request message to thecommunications controller in response to sending the message indicativeof alignment via the first communications channel. Examples of guidancebeacons compatible with certain embodiments described herein include,but are not limited to, magnetic guidance beacons and electromagneticguidance beacons.

In certain embodiments, a method is provided for communicating with awireless electric vehicle charging system including a charging station801 configured to charge an electric vehicle 808. The method includesestablishing a first communications link between the electric vehicle808 and a communications controller of the charging system 800. Themethod further includes exchanging, via the first communications link,one or more service messages with the communications controller of theelectric vehicle 808, the service messages indicative of at least one ofone or more capabilities of the electric vehicle 808 or charging system800, authentication, or authorization for wirelessly receiving powerfrom the charging station 801. The method further includes receiving viathe first communications link, in response to exchanging the one or moreservice messages, a guidance request message indicative of a request forguiding the electric vehicle 808 to the charging station 801. The methodfurther includes sending a message to the charging station to transmitone or more guidance beacons from the charging station 801 forperforming at least one of a guidance operation or an alignmentoperation with the electric vehicle 808. The method further includesreceiving a message from the communications controller (e.g., VCU 810)of the electric vehicle 808 indicative of alignment between the electricvehicle 808 and the charging station 801, the message further comprisingthe identifier of the charging station 801 and an identifier of theelectric vehicle 808. The method further includes receiving a chargingrequest message from the communications controller of the electricvehicle 808 in response to receiving the message indicative of alignmentvia the first communications channel. The method further includessending a message to the charging station 801 to initiate powertransfer. In certain embodiments, the method further includesestablishing a second communications link with the electric vehicle,with the second communication link configured to communicate data viamodulation of the wireless power field used for transferring power tothe electric vehicle. Examples of guidance beacons compatible withcertain embodiments described herein include, but are not limited to,magnetic guidance beacons and electromagnetic guidance beacons.

The first communication link may be “out-of-band” channel based on, forexample, IEEE 802.11 or the like. The second communication link may be achannel that uses magnetic in-band communication (e.g., in-band commandand control communication for electric vehicle charging). The in-bandchannel may reuse existing power charging features and components, forexample by modulating the power carrier field from the base wirelesscharging system 102 a (e.g., primary) and by modulating the load at theelectric vehicle wireless charging system 114 (e.g., secondary).Modulating the power carrier (e.g., modulating the wireless field usedfor power transfer) at the base wireless charging system 102 a mayinclude a variety of types of modulation techniques such as, for exampleamplitude modulation and angle modulation. Angle modulation may includeany type of phase modulation, frequency modulation and the like.Furthermore, modulation may include modulation of the magnetic vectorangle at the base wireless charging system 102 a to accomplishcommunication. In some aspects, such modulation may not add any extrahardware cost since existing components of the base wireless chargingsystem are used for accomplishing the in-band signalling.

The second channel using magnetic in-band communication may be used forlocalized safety and power control signalling. Use of the second in-bandchannel may provide protection against signal interference, jamming, orproviding reduced opportunity for hacking. Other communication may takeplace via the first out-of-band channel.

The base wireless charging system 102 a and the electric vehiclewireless charging system 114 can both implement a wireless channel forcommunication. Each system may have a corresponding communicationcontroller.

In an embodiment, the second in-band channel may be used to ensure thatthe electric vehicle wireless charging system 114 remains in alignmentand that safety is not compromised (due to dedicated safety/powercontrol channel). In addition, the second in-band channel, modulated ator near the carrier frequency or power transfer, may broadcast thedevice identifier (ID) of the base wireless charging system 102 a. Suchbroadcasting of the ID allows for the electric vehicle to communicatewith wireless charging system 114 to determine the ID of the basewireless charging system 102 a while aligning, similar to as describedabove. At the end of alignment, the electric vehicle wireless chargingsystem 114 may send an “alignment completed” message via the firstout-of band channel to a base wireless charging system communicationscontroller, the message including the ID of the vehicle and the ID ofthe base wireless charging system 102 a. For example, a communicationscontroller may coordinate communication for several base chargingstations, as described above with reference to FIG. 8A, and thereforereceive the ID of the vehicle and the ID of the associated base wirelesscharging system 102 a with which the vehicle is positioned for wirelesspower transfer (e.g., the associated base wireless charging system 102 athat the vehicle is positioned over). Magnetic vectoring can also beused, allowing the vehicle to have guidance into the parking spot,followed by alignment with the base wireless charging system.

In certain embodiments, the second in-band-channel may also communicatepower level requests from the electric vehicle wireless charging system114, e.g., by modulating the load. The response from the base wirelesscharging system 102 a can be communicated back in-band by changing thepower level and also via in-band communication.

In an embodiment, when a command has not been sent for a pre-determinedperiod of time, e.g., via the second in-band communication channel,between the electric vehicle wireless charging system 114 and the basewireless charging system, the electric vehicle wireless charging system114 sends a “heartbeat” message to the base wireless charging system 102a. If no response is returned, the electric vehicle wireless chargingsystem 114 starts emergency shutdown procedures. If no message has beenreceived from the electric vehicle wireless charging system 114 within apredetermined period of time, then the base wireless charging system 102a starts emergency shutdown procedures.

In an embodiment, if a live object is detected by the electric vehiclewireless charging system 114, a power pause command is sent.

In an embodiment, the first out-of-band communication channel (e.g., viaIEEE 802.11 or the like) may be used for other features such as forhigh-level commands. Such features may include, for example, optionalvalue-added services, charging and metering. The first out-of-bandchannel may also be used for guidance information, pairing, startingpower transfer, and resuming power transfer. Various power controlmessages generally sent via the second in-band channel may also be sentvia the first out-of-band communication channel.

Furthermore, when a command has not been sent between the communicationcontrollers of the electric vehicle wireless charging system 114 and thebase wireless charging system 102 a for a predetermined amount of time,the base wireless charging system can terminate power transfer. Acommand to terminate power transfer may be sent via the second in-bandchannel, but may also be sent via the first out-of-band channel. Ifbilling parameters and requirements are part of the charging, then theappropriate commands may be sent via the first out-of-band communicationchannel.

Prior to having pairing and power transfer take place, communicationover the first out-of-band channel can be established between theelectric vehicle wireless charging system communication controller andthe base wireless charging system communications controller. In anembodiment, once alignment and pairing are complete, and power transferhas started, then safety and power control messages are exchanged viathe second in-band channel.

As described above, in an aspect, communication via the second in-bandchannel from the electric vehicle wireless charging system to the basewireless charging system may be accomplished by modulation of the field,such as varying the load of the electric vehicle wireless chargingsystem 114.

As further described above, communication over the second in-bandchannel from the base wireless charging system 102 a and the electricvehicle wireless charging system 114 may be accomplished by modulationof the carrier of the power supplied to the vehicle (e.g. anglemodulation of the carrier of the power supplied to the vehicle).

In an embodiment, in order for the second magnetic in-band communicationchannel to be formed/used, initial communication takes place over thefirst out-of-band channel. The following exemplary sequence ofinformation exchanges may be used in accordance with an embodiment,although any combination or orders of the exchanges described below arecontemplated to be in accordance with the principles described herein.First, there may be an association between the communication controllerassociated with the base wireless charging system and the electricvehicle wireless charging system via the first out-of-band channel.Further exchanges of service discovery and service details may takeplace via the first channel. Service discovery may include the exchangeof hardware capabilities via the first channel. In addition, optionallyother exchanges related to service and payment selection, paymentdetails, and contract authentication can take place via the firstchannel.

If the hardware or billing method is not compatible, then the sequencecan terminate. The base wireless charging system 102 a may determine thehardware compatibility, and the electric vehicle wireless chargingsystem may determine the billing compatibility.

After the initial association and other sequences, the communicationcontroller for the electric vehicle wireless charging system can send aguidance request to the communications controller for the base wirelesscharging system via the first channel. The base wireless charging systemthen may activate the guidance beacons of the charging system. Theelectric vehicle 112 can then move to the parking spot where guidanceand alignment may take place.

During guidance and alignment, the electric vehicle wireless chargingsystem 114 can detect guidance beacon(s) and may read an ID for the basewireless charging system 102 a transmitted in the guidance beacon, andcan (optionally) provide guidance to the driver. The ID via the guidancebeacon may be considered via the second in-band channel in some aspects.

As the electric vehicle moves into parking spot, the electric vehiclewireless charging system 114 can switch from guidance to alignment. Theelectric vehicle wireless charging system 114 can continue to detect themagnetic beacon, and can provide alignment information to the driver.The electric vehicle wireless charging system may again read the ID ofthe base wireless charging system 102 a from the guidance beacon.

Once, the electric vehicle 112 comes to a stop, the electric vehiclewireless charging system 114 and the base wireless charging system mayconfirm alignment via the magnetic beacon.

In an embodiment, the communication controller for the electric vehiclewireless charging system 114 sends an message indicating that alignmenthas completed via the first out-of-band channel and may include the IDof the electric vehicle wireless charging system 114 and the ID of thebase wireless charging system. Such communication may be used when acommunication controller for the base wireless charging system 102 s isconnected and manages communications for several base wireless chargingsystems 102 a, 102 b, and the communication controller for the basewireless charging system 102 a may need to know which specific basewireless charging system 102 a the electric vehicle 112 is positioned toinitiate wireless power transfer (e.g., which specific base wirelesscharging system 102 a the electric vehicle 112 is parked over), asdescribed above with reference to FIGS. 8A-8B. Likewise, if thecommunication controller is configured to support a single base wirelesscharging system 102 a, the base wireless charging system can utilizeconfirmation that the electric vehicle is indeed positioned (e.g.,parked over) for wireless power transfer with the specific base wirelesscharging system 102 a.

During a pairing process, the electric vehicle wireless charging system114 can retrieve the ID of the base wireless charging system 102 a, forexample encoded in a magnetic beacon, and can then send a messageindicating alignment is completed to the communication controller of thebase wireless charging system. As described, the message can include theID of the base wireless charging system 102 a and the ID of the electricvehicle wireless charging system 114. If the communication controllerfor the base wireless charging system 102 a does not have a basewireless charging system with that ID, then the communication controllerof the base wireless charging system can reject the message indicatingalignment is completed, implying that the electric vehicle wirelesscharging system is in communication with the wrong communicationcontroller for the base wireless charging system.

If the communication controller for the base wireless charging systemaccepts the message indicating that alignment is complete, then powertransfer can be initiated.

After establishing the first out-of-band communication channel (e.g.,after communicating the message that indicates alignment is complete),if the optional billing features are implemented, the communicationcontrollers for the electric vehicle wireless charging system 114 andthe base wireless charging system 102 a can exchange messages forbilling/metering purposes via the first out-of-band communicationchannel.

In an embodiment, to initiate power transfer, the electric vehiclewireless charging system 114 sends a charging initiation message via thefirst out-of-band channel to the communication controller for the basewireless charging system 102 a. The communication controller for thebase wireless charging system 102 a sends confirmation if the equipmentis functioning properly, otherwise the communication controller for thebase wireless charging system 102 a sends a rejection to thecommunication controller for the electric vehicle wireless chargingsystem 114 and terminates the power transfer. Once power has started totransfer, then the second in-band channel is activated for exchangingfurther power control, messages, etc.

In accordance with the communication exchanges described above, FIG. 12is a flowchart of an exemplary method for exchanging communicationbetween a charging system and an electric vehicle in accordance with anexemplary embodiment.

In an embodiment, examples of requests sent by the electric vehiclewireless charging system 114 to the base wireless charging system 102 avia the first out-of-band channel include but are not limited to:

-   -   Set power level to a specified power level (e.g., to X KW, where        X is the specified number of kilowatts).    -   Set current to a specified current level (e.g., to Y amperes,        where Y is the specified number of amperes).    -   Set voltage to a specified voltage level (e.g., to Z volts,        where Z is the specified number of volts).    -   Pause power transfer (to be restarted via the first channel).    -   Stop power transfer (no more power is desired by the vehicle).

In an embodiment, examples of requests sent by the electric vehiclewireless charging system 114 to the base wireless charging system 102 avia the second in-band channel include but are not limited to:

Change Power Setting.

Fast Stop Charging.

The base wireless charging system may send acknowledgment messages backor may not send acknowledgment message via the second in-band channel.In an embodiment, all other commands and responses are sent via thefirst out-of-band channel.

In an embodiment, the electric vehicle wireless charging system 114 mayterminate power transfer either via the first out-of-band channel or thesecond in-band channel.

Since the baud rate of the second magnetic in-band communication may belower (e.g., as compared to the first channel) in certain embodiments,small binary commands and responses can be used.

In some embodiments, the first out-of-band channel may also be usedin-lieu of the second in-band channel as a backup to second in-bandcommunication.

In one aspect, a potential order of messages may substantially include:service discovery, service details, service and payment selection,payment details, contract authentication, charge parameter discover,power delivery, metering status, metering receipt, and terminatecharging. It should be appreciated that this is one possible order andany other order of the above or exclusion of certain messages arecontemplated according to the embodiments described herein.

FIG. 13 illustrates a flowchart of an exemplary method 900 ofcommunicating with a charging system 800 comprising a plurality ofcharging stations configured to charge an electric vehicle 808, inaccordance with certain embodiments described herein. FIG. 14illustrates a flowchart of an exemplary method 1000 of communicatingwith an electric vehicle 808 in accordance with certain embodimentsdescribed herein. Although the method 900 and the method 1000 aredescribed herein with reference to the electric vehicle 808 andmulti-vehicle and multi-parking parking and charging system 800,discussed above with respect to FIGS. 8A and 8B, a person havingordinary skill in the art will appreciate that the method 900 and themethod 1000 may be implemented by other suitable devices and systems.For example, the method 900 may be performed by a processor orcontroller such as, for example, the VCU 810 (FIG. 8A). For anotherexample, the method 1000 may be performed by a processor or controllersuch as, for example, the BCC 815 (FIG. 8A). Although the method 900 andthe method 1000 are each described herein with reference to a particularorder, in various embodiments, blocks herein may be performed in adifferent order, or omitted, and additional blocks may be added.

In an operational block 910 of the method 900, at least one first signalis transmitted to the charging system 800 via a first communication link(e.g., while the electric vehicle is a first distance from at least onecharging station of a plurality of charging stations). The at least onefirst signal is indicative of a vehicle identifier of the electricvehicle 808. In an operational block 920 of the method 900, at least onesecond signal is received from the at least one charging station of theplurality of charging stations via a second communication link (e.g.,while the electric vehicle is a second distance from the at least onecharging station, with the second distance less than the firstdistance). The at least one second signal is indicative of a chargingstation identifier of the at least one charging station.

In an operational block 1010 of the method 1000, at least one firstsignal from the electric vehicle 808 is received via a firstcommunication link (e.g., while the electric vehicle is a first distancefrom at least one charging station of a plurality of charging stations).The at least one first signal is indicative of a vehicle identifier ofthe electric vehicle 808. In an operational block 1020 of the method1000, at least one second signal is transmitted to the electric vehiclevia a second communication link (e.g., while the electric vehicle is asecond distance from the at least one charging station, with the seconddistance less than the first distance). The at least one second signalis indicative of an identifier of at least one charging station of acharging station 800.

FIG. 15 is a functional block diagram of an apparatus 1100 forcommunicating with a charging system comprising a plurality of chargingstations configured to charge an electric vehicle, in accordance withcertain embodiments described herein. FIG. 16 is a functional blockdiagram of an apparatus 1200 for communicating with an electric vehiclein accordance with certain embodiments described herein. Those skilledin the art will appreciate that the apparatus 1100 and the apparatus1200 may have more components than the simplified block diagrams show inFIGS. 15 and 16. FIGS. 15 and 16 include only those components usefulfor describing some prominent features of implementations within thescope of the claims.

The apparatus 1100 comprises means 1110 for transmitting at least onefirst signal to the charging system via a first communication link(e.g., while the electric vehicle is a first distance from at least onecharging station of a plurality of charging stations), with the at leastone first signal indicative of a vehicle identifier of the electricvehicle. In certain embodiments, the means 1110 for transmitting can beimplemented by the transmitter 819 (FIG. 8A). The apparatus 1100 furthercomprises means 1120 for receiving at least one second signal from atleast one charging station of the plurality of charging stations via asecond communication link (e.g., while the electric vehicle is a seconddistance from the at least one charging station, with the seconddistance less than the first distance), with the at least one secondsignal indicative of a charging station identifier of the at least onecharging station. In certain embodiments, the means 1120 for receivingcomprises the receiver 812 (FIG. 8A).

The apparatus 1200 includes means 1210 for receiving at least one firstsignal from the electric vehicle via a first communication link (e.g.,while the electric vehicle is a first distance from at least onecharging station of a plurality of charging stations), with the at leastone first signal indicative of a vehicle identifier of the electricvehicle. In certain embodiments, the means 1210 for receiving can beimplemented by the receiver 817 (FIG. 8A). The apparatus 1200 furthercomprises means 1220 for transmitting at least one second signal via asecond communication link (e.g., while the electric vehicle is a seconddistance from the at least one charging station, with the seconddistance less than the first distance), with the at least one secondsignal indicative of an identifier of at least one charging station of acharging system. In certain embodiments, the means 1220 for transmittingcomprises the transmitters 803 a-c.

The various operations of methods described above may be performed byany suitable means capable of performing the operations, such as varioushardware and/or software component(s), circuits, and/or module(s).Generally, any operations illustrated in the Figures may be performed bycorresponding functional means capable of performing the operations.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative logical blocks, modules, circuits, andalgorithm steps described in connection with the embodiments disclosedherein may be implemented as electronic hardware, computer software, orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. The described functionalitymay be implemented in varying ways for each particular application, butsuch implementation decisions should not be interpreted as causing adeparture from the scope of the embodiments of the invention.

The various illustrative blocks, modules, and circuits described inconnection with the embodiments disclosed herein may be implemented orperformed with a general purpose processor, a Digital Signal Processor(DSP), an Application Specific Integrated Circuit (ASIC), a FieldProgrammable Gate Array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm and functions described in connectionwith the embodiments disclosed herein may be embodied directly inhardware, in a software module executed by a processor, or in acombination of the two. If implemented in software, the functions may bestored on or transmitted over as one or more instructions or code on atangible, non-transitory computer-readable medium. A software module mayreside in Random Access Memory (RAM), flash memory, Read Only Memory(ROM), Electrically Programmable ROM (EPROM), Electrically ErasableProgrammable ROM (EEPROM), registers, hard disk, a removable disk, a CDROM, or any other form of storage medium known in the art. A storagemedium is coupled to the processor such that the processor can readinformation from, and write information to, the storage medium. In thealternative, the storage medium may be integral to the processor. Diskand disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and blu ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer readable media. The processor andthe storage medium may reside in an ASIC. The ASIC may reside in a userterminal. In the alternative, the processor and the storage medium mayreside as discrete components in a user terminal.

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of the inventions have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any particular embodiment of the invention.Thus, the invention may be embodied or carried out in a manner thatachieves or optimizes one advantage or group of advantages as taughtherein without necessarily achieving other advantages as may be taughtor suggested herein.

Various modifications of the above described embodiments will be readilyapparent, and the generic principles defined herein may be applied toother embodiments without departing from the spirit or scope of theinvention. Thus, the present invention is not intended to be limited tothe embodiments shown herein but is to be accorded the widest scopeconsistent with the principles and novel features disclosed herein.

What is claimed is:
 1. A method of communicating with a charging systemcomprising a plurality of charging stations configured to charge anelectric vehicle, the method comprising: transmitting at least one firstsignal to the charging system via a first communication link while theelectric vehicle is a first distance from at least one charging stationof the plurality of charging stations, the at least one first signalindicative of a vehicle identifier of the electric vehicle; andreceiving at least one second signal from the at least one chargingstation of the plurality of charging stations via a second communicationlink while the electric vehicle is a second distance from the at leastone charging station of the plurality of charging stations, the seconddistance less than the first distance, the at least one second signalindicative of a charging station identifier of the at least one chargingstation.
 2. The method of claim 1, wherein the charging system furthercomprises a communication hub in communication with each chargingstation of the plurality of charging stations, and transmitting the atleast one first signal comprises transmitting the at least one firstsignal to the communication hub.
 3. The method of claim 2, furthercomprising receiving at least one third signal from the communicationhub via the first communication link.
 4. The method of claim 3, whereinthe at least one third signal comprises information regarding anavailability of one or more charging stations of the plurality ofcharging stations for use in charging the electric vehicle.
 5. Themethod of claim 1, wherein the at least one first signal furthercomprises information regarding at least one of: a vehiclecharacteristic, driver of the electric vehicle, or a payment methodexpected to be used.
 6. The method of claim 1, wherein the at least onesecond signal further comprises information regarding at least one of: anumber of available charging stations, a charging stationcharacteristic, a schedule of costs for charging, or a charging menu ofoptions available for charging the electric vehicle using the availablecharging stations.
 7. The method of claim 1, wherein the plurality ofcharging stations are configured to provide wireless power to theelectric vehicle.
 8. The method of claim 1, further comprisingtransmitting at least one third signal to the charging system via thefirst communication link, the at least one third signal indicative ofthe charging station identifier.
 9. The method of claim 1, wherein theat least one charging station is configured to detect whether anon-electric vehicle is parked at the at least one charging station. 10.The method of claim 1, further comprising allocating the at least onecharging station to charging of the electric vehicle.
 11. The method ofclaim 1, further comprising determining an optimal charging station ofthe at least one charging station to allocate to charging of theelectric vehicle.
 12. The method of claim 1, further comprising turningon and off a transmitter of the electric vehicle to avoid transmittingthe at least one first signal during times at which such transmission isnot desired.
 13. The method of claim 1, wherein receiving the at leastone second signal from the at least one charging station occurs whilethe electric vehicle is within a parking space in which the at least onecharging station is positioned and while the electric vehicle is notable to receive signals from other charging stations of the plurality ofcharging stations.
 14. The method of claim 1, further comprising usingthe second communication link for one or more of: electric vehicleguidance, electric vehicle alignment, charging control, statuscommunication, authorization, identification, or payment management. 15.A method of communicating with an electric vehicle, the methodcomprising: receiving at least one first signal from the electricvehicle via a first communication link while the electric vehicle is afirst distance from at least one charging station of a charging system,the at least one first signal indicative of a vehicle identifier of theelectric vehicle; and transmitting at least one second signal to theelectric vehicle via a second communication link while the electricvehicle is a second distance from the at least one charging station ofthe charging system, the second distance less than the first distance,the at least one second signal indicative of an identifier of the atleast one charging station of the charging system.
 16. The method ofclaim 15, wherein the charging system comprises a communication hub incommunication with each charging station of the at least one chargingstation, and receiving the at least one first signal comprises receivingthe at least one first signal by the communication hub.
 17. The methodof claim 16, further comprising transmitting at least one third signalfrom the communication hub to the electric vehicle via the firstcommunication link.
 18. The method of claim 17, wherein the at least onethird signal comprises information regarding an availability of one ormore charging stations of the at least one charging station for use incharging the electric vehicle.
 19. The method of claim 15, wherein theat least one first signal further comprises information regarding atleast one of: a vehicle characteristic, driver of the electric vehicle,or a payment method expected to be used.
 20. The method of claim 15,wherein the at least one second signal further comprises informationregarding at least one of: a number of available charging stations, acharging station characteristic, a schedule of costs for charging, or acharging menu of options available for charging the electric vehicleusing the available charging stations.
 21. The method of claim 15,wherein the at least one charging station is configured to providewireless power to the electric vehicle.
 22. The method of claim 15,further comprising receiving at least one third signal from the electricvehicle via the first communication link, the at least one third signalindicative of the charging station identifier.
 23. The method of claim15, wherein the at least one charging station is configured to detectwhether a non-electric vehicle is parked at the at least one chargingstation.
 24. The method of claim 15, further comprising determining anoptimal charging station of the at least one charging station toallocate to charging of the electric vehicle.
 25. A communication systemof an electric vehicle, the communication system comprising: atransmitter configured to transmit at least one first signal to acharging system via a first communication link while the electricvehicle is a first distance from at least one charging station of aplurality of charging stations of the charging system, the at least onefirst signal indicative of a vehicle identifier of the electric vehicle;and a first receiver configured to receive at least one second signalfrom the at least one charging station of the plurality of chargingstations via a second communication link while the electric vehicle is asecond distance from the at least one charging station, the seconddistance less than the first distance, the at least one second signalindicative of a charging station identifier of the at least one chargingstation.
 26. The communication system of claim 15, wherein the chargingsystem further comprises a communication hub in communication with eachcharging station of the plurality of charging stations, and thetransmitter is configured to transmit the at least one first signal tothe communication hub, and the communication system further comprises asecond receiver configured to receive at least one third signal from thecommunication hub via the first communication link.
 27. Thecommunication system of claim 26, further comprising a transceiver thatcomprises the transmitter and the second receiver, and the at least onethird signal comprises information regarding an availability of one ormore charging stations of the plurality of charging stations for use incharging the electric vehicle.
 28. A charging system comprising: areceiver configured to receive at least one first signal from anelectric vehicle via a first communication link while the electricvehicle is a first distance from at least one charging station of thecharging system, the at least one first signal indicative of a vehicleidentifier of the electric vehicle; and a plurality of charging stationscomprising the at least one charging station, the plurality of chargingstations configured to charge the electric vehicle, each chargingstation of the plurality of charging stations comprising a firsttransmitter configured to transmit at least one second signal via asecond communication link while the electric vehicle is a seconddistance from the at least one charging station, the second distanceless than the first distance, the at least one second signal indicativeof an identifier of the at least one charging station of the pluralityof charging stations.
 29. The charging system of claim 28, wherein thecharging system further comprises a communication hub in communicationwith each charging station of the plurality of charging stations, thecommunication hub comprising the receiver.
 30. The charging system ofclaim 28, wherein the at least one charging station is configured todetect whether a non-electric vehicle is parked at the at least onecharging station.